DE102011015753A1 - Injector - Google Patents

Abstract

An injection valve according to the invention for injecting fuel into a combustion chamber of an internal combustion engine comprises a valve housing (18) and a valve member (E1) displaceably arranged therein for opening and closing at least one injection opening (14) and having a plurality of valve member elements arranged one behind the other in the longitudinal direction (8, 11a, 11b, 11c, 12a, 12b) and at least one coupling element (9a, 9b, 9c, 9d), wherein the coupling element (9a, 9b, 9c, 9d) encloses an end portion of a first valve member element such that between an outer surface (24a, 24b) of the end portion of the first valve member element and a first inner surface of the coupling element (9a, 9b, 9c, 9d) an annular gap (26) remains to compensate for an angular error (W1) between a longitudinal axis of the first valve member element and a longitudinal axis of the Coupling element (9a, 9b, 9c, 9d).

Description

The present invention relates to an injection valve for fuel injection in a combustion chamber of a combustion stapling machine, for example a diesel engine.

Such injectors are used in particular for the intermittent injection of a present in liquid form of fuel, for example, gasoline or diesel fuel, in a combustion chamber of an internal combustion engine. For this purpose, the fuel is provided by a high-pressure pump at a high pressure and injected into the combustion chamber through the injection valve arranged on the combustion chamber, for example a cylinder of a diesel or gasoline engine. The injection process is usually controlled by an electronic engine control.

Such an injection valve comprises a housing, which is usually elongated for reasons of the available installation space and in which an elongated valve member is displaceably arranged. By displacing the valve member, an injection port disposed in a valve seat member can be closed or opened. On the housing, a high-pressure fuel port is provided, which communicates via a bore in communication with the injection port. Furthermore, the injection valve comprises an actuator, which can be controlled via a control device, in particular the electronic engine control, and a typically hydraulic control device, with which the activity of the actuator can be converted into a movement of the valve member. Such actuators and control devices are known per se and, for example, in the EP 0 976 924 A2 or the EP 0 228 578 A1 described. An injection valve of the type mentioned is, for example, in WO 02/086309 A1 disclosed.

The length of the valve member of such an injector is usually much larger than the diameter of the valve member. The large ratio of length to diameter can lead to many disadvantages. Thus, long, thin components are more difficult to produce than short, thick components, which leads to higher production costs. In addition, an injection valve member is usually subjected to a heat treatment during its processing, which can lead to a disadvantageous for the use delay of the valve member.

It has therefore been proposed to implement an injection valve member in several parts, wherein the individual elements are in operative connection with each other during operation. This also makes it possible to produce the highly stressed seat from a high quality, expensive material, while the rest of the injection valve member can be made of a low cost material. In addition, a multi-part design of the valve member allows a modular design in which at least individual elements of the valve member for a plurality of engine types can be used, even if these different lengths of the valve members are necessary. As a result, a production in coarser, less expensive lot sizes is possible.

Since even with the elements of a multi-part valve member due to a heat treatment can occur and also manufacturing inaccuracies can lead to non-parallelism and / or misalignment of the axes of the individual elements of the valve member, it would be desirable if such errors could be tolerated without adverse consequences ,

In the EP 0 685 645 B1 an injection valve for a fuel injection system of an internal combustion engine is described, wherein in a valve housing, a multi-part valve body with a nozzle needle and a coaxially arranged to this overlying valve body part is slidably disposed. The fuel passes from an inlet line via a laterally arranged in the valve housing bore in a nozzle needle adjacent pressure chamber. In order to avoid overloading of the nozzle tip of the valve at an increased closing speed, a damping chamber filled with fuel is provided between the nozzle needle and the overlying valve body part. An operative connection between the nozzle needle and the overlying valve body part can be imparted by a ring element into which the nozzle needle protrudes approximately free of play. An articulated function is exercised by a ring element made of plastic, which is inserted over the two ends of the nozzle needle and the valve body part and together with these forms a tight fit. The damping chamber can be connected via a throttle bore with the pressure chamber.

However, a plastic ring member is not satisfactory in durability due to the chemical, thermal and mechanical conditions prevailing in the injector. Further, for the exercise of the articulated function, a deformation of the ring member is necessary, whereby lateral forces are exerted on the nozzle needle and the overlying valve body part or the respective guides, which lead to friction and wear, which ultimately affects the function of the injector.

It is therefore an object of the present invention to provide an injection valve of the type mentioned, which is insensitive to angular and Koaxialitätsfehlern, wherein said disadvantages are avoided.

This object is achieved by an injection valve according to claim 1.

An injection valve according to the invention for fuel injection into a combustion chamber of an internal combustion engine, for example an Otto or a diesel engine, comprises a valve housing and a valve member which is displaceably arranged in the valve housing for opening and closing at least one injection opening in a longitudinal direction. The injection opening can be arranged for the ice spraying of the fuel in the combustion chamber and is formed for example by a valve seat member associated with the housing. The valve member is elongated in particular in the longitudinal direction and comprises a plurality of valve member elements arranged one behind the other in the longitudinal direction. Of these, at least one valve member element can be designed to open and close the injection opening; Furthermore, at least one valve member element may be provided on which a drive of the valve member engages.

The valve member according to the invention further comprises a coupling element for coupling a first valve member element with a second valve member element. In this case, the first valve member element can be arranged on the nozzle side of the second or vice versa. The coupling element may be sleeve-shaped and surrounds an end region of the first valve member element such that an annular gap is formed between an outer surface of the end region of the first valve element element and a first inner surface of the coupling element. The coupling element may comprise further elements for connection to the first and the second valve member element. The end region of the first valve member element and a region of the coupling element enclosing the latter can be approximately configured as full or hollow cylinders with a circular cross section, so that the outer surface of the end region of the first valve element element and the first inner surface of the coupling element are approximately circular cylindrical. The annular gap can have a uniform or an uneven width along the circumference of the first valve member element.

Characterized in that between an outer surface of the end portion of the first valve member member and a first inner surface of the coupling element, an annular gap is present, a compensation of an angular error between a longitudinal axis of the first valve member element and a longitudinal axis of the coupling element allows. In particular, the clearance ensured by the annular gap makes it possible to tilt the first valve element element relative to the coupling element, without having to apply a force for deforming the coupling element from the guides of the valve element. Since no bending of the coupling element or the first valve member element is necessary to compensate for the angular error, they can be made of durable materials of high rigidity, such as steel, in particular hardened steel. In this way an operative connection between the first and the second valve member element is mediated, which allows actuation of the valve member for opening and closing the injection opening, but for example, deformations and guiding errors of the valve member elements can be tolerated.

Preferably, the longitudinally measured length of the annular gap and the width of the annular gap are dimensioned such that an angular error of at least approximately 2 '(2 arc minutes) can be compensated. This corresponds to a deviation of, for example, about 0.01 mm to a length of 15 mm. As a result, based on manufacturing tolerances achievable with conventional means tolerances the resulting angular error can be compensated usually, creating a cost-effective production is possible.

According to a preferred embodiment of the invention, the valve member, in particular the coupling element, at least partially surrounded by a pressurized fluid. In particular, the valve member is surrounded during operation of the injection element in the region of the opening of the annular gap of the pressurized fluid. Upon application of a tensile force to the valve member, whereby the protruding into the coupling element first valve member element and the second valve member element, which may be connected to the coupling element in other ways than the first, are pulled apart, arises in an interior of the coupling element, in which the first Valve member element protrudes and which, apart from the annular gap, is closed or sealed, a negative pressure. Due to the negative pressure pressure fluid can flow through the annular gap in the interior. The annular gap is dimensioned such that at least for a period during which the tensile force acts to perform an injection, a sufficiently small amount of liquid flows into the interior to maintain the negative pressure substantially upright. The annular gap is thus dimensioned such that the kinematic coupling of the first and a second valve member element adjacent in the longitudinal direction is maintained at least for this period of time. The annular gap can for this purpose have a width in the micrometer range, for example of a maximum of about 5 microns. The first and the second valve member element are at least as far surrounded by the pressurized fluid, so that by the negative pressure in relation to the surrounding pressure of the pressurized fluid and possibly taking into account other forces, such as a spring, a corresponding movement of the first and the second valve member element is triggered , This will created an operative connection for transmitting the tensile force or the longitudinal movement of the valve member, which allows the compensation of the angular error without exerting substantial lateral forces. A further connection between the first and the second valve member element is not necessary.

When a pressure force in the longitudinal direction acts on the valve member for closing the at least one injection opening or for triggering a corresponding acceleration of a valve member element, the pressure fluid can escape through the annular gap. In particular, when the pressure force acts for longer periods than the tensile force, it may be provided that the pressurized fluid escapes so much from the interior of the coupling element, that the end portion of the first valve member element in contact with an end portion of the second valve member element or with a corresponding trained stop of the coupling element passes. As a result, a secure transmission of the pressure force is possible.

According to a particularly preferred embodiment of the invention, the valve member on all sides or practically on all sides of the pressurized fluid umber; at least during the injection process, the valve member is surrounded on all sides or practically on all sides by the pressurized fluid. In particular, when the valve member is surrounded on all sides or practically on all sides by the pressurized fluid, occurs during the execution of an injection process, the situation that acts within the valve member, a tensile force. The annular gap is dimensioned such that upon application of a tensile force to the valve member in the interior of the coupling element, a negative pressure is formed; the negative pressure is used to transmit the tensile force between the first and second valve member element. Thus, no further connection between the first and the second valve member element is necessary to transmit the resulting in the execution of the injection process tensile force. The fact that the valve member can be surrounded on all sides or practically on all sides by the pressure fluid, a particularly simple design is possible; In particular, no pressure-tight sealing of the valve member is required.

In a particularly advantageous manner, the annular gap is dimensioned such that upon application of the tensile force to the valve member such a small amount of the pressurized fluid penetrates into the interior of the coupling element, that there is no significant damping of the movement of the valve member. In particular, the movement of a nozzle-remote of the first or the second valve member element is thus transferred to a nozzle closer of the two interconnected valve member elements without substantial relative movement of the two valve member element takes place with each other. Such a relative movement would reduce the control of the injection process, in particular the control of the movement of a nozzle needle.

The coupling element is preferably designed such that it is deformed under the effect of the negative pressure, so that the width of the annular gap to maintain the negative pressure is reduced. For this purpose, the coupling element may be formed thin-walled at least in a partial region which encloses the end region of the first valve member element. Due to the prevailing in the interior of the coupling element negative pressure compared to the external pressure of the pressure fluid, the coupling element is compressed in the micrometer range, so that the width of the annular gap is reduced and the inflowing amount of the pressurized fluid is reduced. Due to the deformation, the coupling element can even enclose the end region of the first valve member element in a sealing manner under the effect of the negative pressure. As a result, the transmission of a lifting movement of the valve member is further improved.

In particular, the pressurized fluid is pressurized liquid fuel or fuel that can be supplied via a high-pressure port of the housing. Characterized in that the fuel to be injected is used as the pressurized fluid for mediating the coupling between the first and the second valve member element, a particularly simple and safe execution of the injection process is achieved.

Preferably, the injection valve according to the invention is designed as an injection valve of an injection system with a common high-pressure supply. Such an injection system is characterized by a high-pressure pump which provides the fuel to be injected at a high pressure, for example 100 bar to over 2500 bar, of a plurality of injection valves via a common high-pressure line system. Such injection systems are therefore also referred to as common rail systems. The high-pressure supply of the injection valves in such an injection system is known per se. The injectors effect an intermittent injection of the high pressure fuel into the combustion chamber of an internal combustion engine, the injections typically being controlled by an electronic engine controller.

Furthermore, it is preferred that the valve member is guided in a central bore of the valve housing and the fuel from the high pressure port through the central bore to the injection port can be fed. Due to the fact that the fuel in the same space of the housing in which the Valve member is arranged, is guided to the injection port, can be ensured in a simple manner that the valve member, in particular the coupling element, is surrounded by pressurized fuel and thereby even when applying a tensile force an operative connection between the first and the second valve member element due to the Interior of the coupling element due to the tensile force resulting negative pressure exists. The fact that the valve member and the fuel are guided in a central bore, a simple and inexpensive production is possible.

According to a preferred embodiment of the invention, the first inner surface of the coupling element and / or the outer surface of the end region of the first valve member element seen in longitudinal section is formed crowned. Seen spatially, the first inner surface of the coupling element is thus spindle-shaped or the outer surface of the end region of the first valve member element is barrel-shaped. The deviations from a cylindrical, in particular circular cylindrical shape can be dimensioned such that a compensation of angular errors to the desired extent, however, the width of the annular gap, in particular in a central region is sufficiently low to the inflow of pressurized fluid into the interior of the coupling element so far to limit that maintaining a sufficient negative pressure for a time sufficient for actuation of the valve member is ensured or that a sufficiently small amount of fluid penetrates into the interior, so that no significant damping occurs. As a result, a compensation of larger angle errors while maintaining the operative connection between the first and a second valve member element can be made possible.

According to a further preferred embodiment, the first inner surface of the coupling element and / or the outer surface of the end region of the first valve member element may be frusto-conical. In addition, a crown may be superimposed in the manner described. This also makes it possible to compensate for larger angle errors while maintaining the operative connection.

Furthermore, it can be provided in an advantageous manner that between the end region of the first valve member element and an end region of a second valve member element, d. H. in an interior of the coupling element, at least one spacer is arranged or can be arranged. The at least one spacer is formed in particular for transmitting a compressive force between the first and the second valve member element. As a result, length deviations of the valve member elements can be compensated. It can also be provided that according to the dimensions and the number of spacers different length coupling elements can be used.

According to one embodiment of the invention, the coupling element is fixedly connected to a second valve member element, for example, shrunk or connected by soldering, or integrally formed with the second valve member element, d. H. integrated with this into a component. As a result, a particularly simple, firm and secure connection for the transmission of tensile and compressive forces within the valve member is achieved.

Alternatively, the coupling element may enclose an end region of a second valve element element such that an annular gap for compensating an angular error between a longitudinal axis of the second valve element element and a longitudinal axis of the coupling element is formed between an outer surface of the end region of the second valve element element and a second inner surface of the coupling element. The coupling element is connected according to this embodiment, in particular in a corresponding manner with the second valve member element as with the first valve member element. As a result, the first and the second valve member element are coupled to each other such that both in the connection of the first and in the connection of the second valve member element with the coupling element, a compensation of an angle error is made possible. As a result, a larger angle error can be compensated for overall, but it is also possible to compensate for a radial offset of the axes of the first and the second valve member element.

According to a further preferred embodiment of the invention, the valve member comprises more than two valve member elements, which are operatively connected by a plurality of coupling elements. As a result, a simpler and more cost-effective production than when using correspondingly longer undivided valve member elements is possible. Furthermore, a larger angle error and in particular a larger radial offset can be compensated thereby.

In particular, the valve member may comprise a valve member formed as a nozzle needle, which is designed to open and close the injection opening. At the end opposite the nozzle needle, the valve member has a control part, which can be driven via an actuatable by means of an actuator control device. The control part is thus displaced due to the action of the actuator and drives the valve member to its movement in the longitudinal direction. For this purpose, suitable actuators or control devices are known per se. In particular, the actuator can be a from a control unit, such as an electronic Motor control, electromagnetically actuated valve which controls the flow of pressurized fluid from a control room. When the pressure fluid from the control chamber expires, the control part follows, so that the valve member releases the injection opening; On the other hand, when the pressurized fluid fills the control space, the valve member is moved in the reverse direction by a spring for closing the injection port.

The valve member may comprise only two valve member elements, namely the valve member element designed as a nozzle needle and the control part, wherein these two valve member elements are in operative connection via a coupling element described above; However, the valve member may also have more than two valve member elements, wherein more than one coupling element of the type described may be present. The coupling element or the coupling elements can also be integrated into a valve member element, d. H. be formed integrally with this.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Further aspects of the invention will become apparent from the following description of a preferred embodiment and the accompanying drawings. In a schematic representation:

1 a longitudinal section of an embodiment of an injection valve according to the invention;

2 an enlarged section 1 ;

3 in an enlarged view in longitudinal section, the geometric relationships on a coupling element according to the in 1 and 2 embodiment shown in a misalignment;

4 a cross-sectional view along in 3 shown level DD;

5 a coupling element according to a further embodiment of the invention in longitudinal section;

6 a coupling element according to another embodiment of the invention, also in longitudinal section;

7 a coupling element according to a further embodiment of the invention in longitudinal section;

8th a coupling element according to a further embodiment of the invention in longitudinal section.

When in 1 illustrated embodiment of the invention, an injection valve comprises a housing 18 , a the housing 18 assigned and with this over a holding part 16 firmly connected valve seat element 13 and an actor 1 , The valve seat element 13 has an injection port 14 on; There may also be several injection openings. The injection opening 14 can through a seat part 12a one inside the housing 18 arranged valve member E1 are closed. The valve member E1 is formed thin and elongated and at least partially in a central bore 17 of the housing 18 arranged in which it is slidably guided in its longitudinal direction; For this purpose, suitable guides may be present (not shown). The valve member E1 comprises adjacent to the seat part 12a a spacer 11a and a control part 8th that have coupling elements 9a . 9b coupled together. The seat part 12a , the spacer 11a and the control part 8th For example, each may have a diameter of about 4 mm and strung together give a total length of the valve member E1 of about 130 mm. The housing 18 has a high-pressure fuel connection 10 through which high pressure liquid fuel is supplied. The high-pressure fuel connection 10 is with the central hole 17 connected by the fuel through to the injection port 14 arrives. The valve member E1 is thus largely surrounded by the fuel under high pressure.

At the end of the case 18 , which is the valve seat element 13 is opposite, is an actor 1 arranged, which may for example comprise an electromagnet (not shown). The actor 1 forms together with a sealing seat 2 , an outlet throttle 3 , a control room 4 , an inlet throttle 5 , a spring 6 and a matching spring plate 7 a control device S1. The face 21 of the control part 8th limited as effective area the control room 4 ,

The actor 1 can be caused via an unillustrated control unit to the sealing seat 2 release. It can now be pressurized fuel through the drain throttle 3 from the control room 4 escape, the virtually pressure-free via a symbolically represented return line back into a tank 22 can flow. As the control room 4 only via an inlet throttle 5 with the high-pressure fuel connection 10 connected, the pressure in the control room decreases 4 until the injection valve member E1, consisting of control part 8th , Spacer 11a , Seat part 12a and the two coupling elements 9a . 9b , from his seat 15 emotional. This will turn fuel into an in 1 injected combustion chamber, not shown.

If the injection is to be ended, the actuator becomes 1 caused by the control unit, the sealing seat 2 to close. Thus, no fuel on the outlet throttle 3 more escape and the pressure in the control room 4 increases. With the help of the spring 6 , which deals with her spring plate 7 is supported on the injection valve member E1, this is in his seat 15 pressed and the injection is stopped.

The functioning of the actuator 1 or the control device S1 is described here only by way of example. There are also other embodiments of the actuator 1 or the control device S1 for controlling the movement of the valve member E1, which can also be used in the context of the present invention.

2 shows a coupling element 9b , causing the spacer 11a and the seat part 12a are actively connected. The coupling element 9b is at least as strong with the spacer 11a connected to that function to mediate the movement of the spacer 11a to the seat part 12a is guaranteed. The coupling element 9b could, for example, on the spacer 11a shrunk, pressed or soldered, with other types of connections are conceivable. On the side of the seat part 12a owns the coupling element 9b an inner surface, as a substantially circular cylindrical annular surface 19a is formed and with a clearance fit the seat part 12a at its end portion, which is a substantially circular cylindrical outer surface 24a has, encloses. Between the outer surface 24a and the ring surface 19a is thus an annular gap 26 available. The clearance is so sufficiently sealed or the annular gap 26 sufficiently tight that in a lifting movement in the opposite direction to the seat 15 (S. 1 ) in the interior 20 of the coupling element 9a at least one such negative pressure sets that with the resulting force and possibly one between ring surface 19a and outer surface 24a acting friction force the seat part 12a from his seat 15 is pulled.

The annular gap 26 may initially be slightly wider than is necessary for a sufficiently long maintenance of the negative pressure. The at the beginning of the stroke movement in the interior 20 Coming pressure drop may be sufficient to the coupling element 9b to deform so that the clearance is reduced or the annular gap 26 gets closer. As a result, the clearance can be sufficiently sealed, so that a sufficient negative pressure is maintained long enough to the seat part 12a from the seat 15 (S. 1 ) to draw. Preferably, this is the coupling element 9b at least in the area of its ring surface 19a thin-walled. However, the clearance must be at least so tight that at the start of the stroke movement sufficient for the deformation pressure drop comes about.

In 2 is shown in the ideal case, in which the longitudinal axes of seat part 12a and spacer 11a match and a common longitudinal axis 23 form; the coupling element 9b can also be rotationally symmetrical, so that a longitudinal axis of the coupling element 9b also with the long axis 23 coincides. For example, by inaccuracies in the manufacture of the valve member elements 8th . 11a . 12a or the housing 18 However, deviations between the individual axes can arise, which are compensated according to the invention. This will be explained below on the basis of 3 and 4 explained.

In 3 is the lower part of the coupling element 9b and the end portion of the seat portion 12a that the outer surface 24a has shown. The spacer 11a is in 3 Not shown. As in 3 shown, the longitudinal axis of the seat part 12a opposite the longitudinal axis of the coupling element 9a that here with that of the spacer 11a to be tilted by an angle W1. As in 3 not shown to scale, are the diameter D1 of the annular surface 19a , ie the inner diameter of the coupling element 9a , and the diameter D0 of the outer surface 24a the end portion of the seat part 12a such that between the ring surface 19a and the outer surface 24a an annular gap 26 consists. The width of the annular gap is ½ (D1 - D0) in a symmetrical arrangement.

The angle error W1 caused by the connection between the coupling element 9a and seat part 12a can be compensated, the larger, the greater the width of the annular gap 26 is and the shorter the length L1 of the clearance between the substantially circular cylindrical annular surface 19a and the outer surface 24a is. Is in 3 for a given diameter D0 and given angular error W1, the length L1 of the annular surface 19a enlarged, so must the diameter D1 of the ring surface 19a and thus the width of the annular gap 26 increase the angle error W1 without deformation of the coupling element 9b or the seat part 12a compensate.

In 4 is the in 3 shown situation as a cross section in the plane DD shown. In the plane DD is the annular gap 26 over the circumference of the end portion of the seat part 12a unevenly wide. For the gap widths S2, S3 measured at two opposing positions (see also FIG 3 ): S2 + S3 = D1 - D0

The wider the annular gap 26 is, ie, the greater S2 or S3, the lower the sealing effect of the clearance between the annular surface 19a and the outer surface 24a the end portion of the seat part 12a , The sealing effect may be a certain Do not fall short of measure to ensure that the pressure in the interior 20 of the coupling element 9a can fall off so far during a stroke that the seat part 12a with the spacer 11a can be brought along. Furthermore, the sealing effect should be sufficiently large, so that during the lifting movement only a small amount of the pressurized fluid in the interior 20 of the coupling element 9b flows in and between the end portion of the seat part 12a and this adjacent end portion of the spacer 11a arrives. The amount should in particular be so low that no appreciable attenuation by a between the end portion of the seat part 12a and the spacer 11a formed liquid cushion takes place. This is intended in particular also in the case of the reciprocating motion following the reverse movement, that is to say when a compressive force is exerted in the valve member E1 for closing the injection nozzle 14 , be valid. This will provide improved control over the movement of the seat part 12a allows and reducing the Nutzhubs of the seat part 12a and thus a reduction of the flow through the valve seat member 13 and the injection port 14 avoided, which is advantageous especially for multiple injections and correspondingly short activation duration of the valve member E1. The relative movement of the seat part 12a relative to the spacer 11a or to the control part 8th should be so low in an advantageous manner that reduces the injection amount at the full load point of the engine at the same drive time of the valve by less than 3% by the relative movement.

The amount of per unit time through the annular gap in the interior 20 of the coupling element 9b inflowing pressure fluid is at a given pressure difference in the simplest case approximately proportional to the cube of the width of the annular gap and inversely proportional to the length L1 of the clearance. The combination of the diameters D0, D1 and the length L1 is therefore to be chosen so that on the one hand the clearance is sufficiently tight, on the other hand, a compensation of the angular error W1 via an inclined position of the end portion of the seat part 12a in the annular gap 26 takes place and not or not to a significant extent via a deformation of the coupling element 9b or the end portion of the seat part 12a because such a deformation would lead to high side forces on the injection valve member E1, which would be problematic for its function.

Preferably, the width of the annular gap 26 and the length L1 of the annular surface 19a chosen so that an angular error W1 of at least about 2 'is allowed. At a width of the annular gap 26 of a maximum of about 2 microns and a length L1 of about 6 mm, such an angle error can still without deformation of the coupling element 9a or the seat part 12a be compensated. Such a clearance fit is economical to produce, in this way also a usually strong enough and sufficiently articulated connection between the spacer 11a and the seat part 12a can be achieved. The coupling element 9b can also be designed such that by the interior 20 in a lifting movement resulting negative pressure the coupling element 9b deformed and the width of the annular gap 26 is reduced; With an inner diameter D1 of approximately 4 mm, a wall thickness in the relevant region of the coupling element can be achieved when using non-hardened steel 9b be suitable by about 0.4 mm.

In principle, the same considerations apply when the coupling element 9b with the seat part 12a is firmly connected and the spacer 11a forming an annular gap from the coupling element 9b is enclosed. The spacer 11a can in the same way by a coupling element 9a with the control part 8th be active, as in the 3 and 4 for the connection between seat part 12a and spacer 11a is shown. If the injection valve member E1 comprises more than one coupling element, as a whole, a radial offset of the axes of the interconnected elements can be compensated.

At the in 5 illustrated further embodiment, the coupling element is integral with a spacer 11b executed. The ring surface 19b is therefore the distance piece 11b educated. A separate component, which takes over the coupling function, is eliminated.

Another embodiment is in 6 shown. Here has a coupling element 9c two inner surfaces, each as ring surfaces 19c . 19d are formed. This will be the seat part 12a and the spacer 11c articulated with the coupling element 9c and connected with each other. As a result, a larger angle error or a radial offset can be compensated.

According to 7 can a spacer 25 between the spacer 11a and the seat part 12a be provided, which from the coupling element 9b is enclosed. The spacer may for example consist of hardened steel.

In 8th a simplified embodiment is shown. The ring surface forms 19e at the same time the receptacle for the spacer 11d , so that the coupling element 9d has only a single inner diameter. The outer surface 24b the end portion of the seat part 12b is the corresponding diameter to form an annular gap 26 customized.

For clarity, not all figures are shown in all figures. To a Figure unexplained reference numerals have the same meaning as in the other figures.

LIST OF REFERENCE NUMBERS

E1

valve member

S1

control device

1

actuator

2

sealing seat

3

outlet throttle

4

control room

5

inlet throttle

6

feather

7

spring plate

8th

control part

9a, 9b, 9c, 9d

coupling element

10

Fuel high-pressure connection

11a, 11b, 11c

spacer

12a, 12b

seat part

13

Valve seat member

14

Injection port

15

Seat

16

holding part

17

Central drilling

18

casing

19a, 19b, 19c, 19d, 19e

ring surface

20

inner space

21

face

22

tank

23

longitudinal axis

24a, 24b

outer surface

25

spacer

26

annular gap

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0976924 A2 [0003]
• EP 0228578 A1 [0003]
• WO 02/086309 A1 [0003]
• EP 0685645 B1 [0007]

Claims (14)

Injection valve for fuel injection into a combustion chamber of an internal combustion engine with a valve housing ( 18 ) and a in this for opening and closing at least one injection opening ( 14 ) in a longitudinal direction displaceably arranged valve member (E1) having a plurality of longitudinally successively arranged valve member elements ( 8th . 11a . 11b . 11c . 12a . 12b ) and at least one coupling element ( 9a . 9b . 9c . 9d ), characterized in that the coupling element ( 9a . 9b . 9c . 9d ) encloses an end region of a first valve member element such that between an outer surface ( 24a . 24b ) of the end region of the first valve member element and a first inner surface of the coupling element (FIG. 9a . 9b . 9c . 9d ) an annular gap ( 26 ) remains to compensate for an angular error (W1) between a longitudinal axis of the first valve member element and a longitudinal axis of the coupling element ( 9a . 9b . 9c . 9d ). Injection valve according to claim 1, characterized in that the length measured in the longitudinal direction and the width of the annular gap ( 26 ) are dimensioned such that an angle error (W1) of at least 2 ' can be compensated. Injection valve according to claim 1 or 2, characterized in that the valve member (E1), in particular the coupling element ( 9a . 9b . 9c . 9d ) is at least partially surrounded by a pressurized fluid and that the annular gap ( 26 ) is dimensioned such that upon application of a tensile force to the valve member (E1) in an interior space ( 20 ) of the coupling element ( 9a . 9b . 9c . 9d ) A negative pressure is formed. Injection valve according to claim 3, characterized in that the valve member (E1) is at least temporarily surrounded on all sides by the pressurized fluid. Injection valve according to claim 3 or 4, characterized in that the annular gap ( 26 ) is dimensioned such that upon application of the tensile force to the valve member (E1) in the interior ( 20 ) of the coupling element ( 9a . 9b . 9c . 9d ) penetrates such a small amount of the pressurized fluid that no substantial damping of the movement of the valve member takes place. Injection valve according to one of claims 3 to 5, characterized in that the coupling element ( 9a . 9b . 9c . 9d ) is formed such that it deforms under the effect of the negative pressure and the width of the annular gap ( 26 ) is reduced to maintain the negative pressure. Injection valve according to one of claims 3 to 6, characterized in that the pressurized fluid is pressurized fuel, which via a high pressure port ( 10 ) of the housing ( 18 ) can be fed. Injection valve according to claim 7, characterized in that the valve member (E1) in a central bore ( 17 ) of the valve housing ( 18 ) and the fuel from the high pressure port ( 10 ) through the central bore ( 17 ) to the injection opening ( 14 ) can be fed. Injection valve according to one of the preceding claims, characterized in that the first inner surface of the coupling element ( 9a . 9b . 9c . 9d ) and / or the outer surface ( 24a . 24b ) of the end portion of the first valve member element is crowned. Injection valve according to one of the preceding claims, characterized in that between the end region of the first valve member element and an end region of a second valve member element at least one spacer ( 25 ) is arranged. Injection valve according to one of the preceding claims, characterized in that the coupling element ( 9a . 9b . 9c . 9d ) Is firmly connected to a second valve member element or formed integrally therewith. Injection valve according to one of claims 1 to 10, characterized in that the coupling element ( 9c ) surrounds an end region of a second valve member element such that between an outer surface ( 24a ) of the end region of the second valve member element and a second inner surface of the coupling element an annular gap ( 26 ) remains to compensate for an angular error between a longitudinal axis of the second valve member element and a longitudinal axis of the coupling element ( 9c ). Injection valve according to one of the preceding claims, characterized in that the valve member (E1) has a plurality of coupling elements ( 19a . 19b . 19c . 19d . 19e ) and more than two valve member elements ( 8th . 11a . 11b . 11c . 12a . 12b ). Injection valve according to one of the preceding claims, characterized in that the valve member (E1) by a at one of the injection port ( 14 ) arranged opposite end and by means of an actuator ( 1 ) operable control device (S1) is displaceable.

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